The present invention relates to a semiconductor device, and is preferably applicable to, for example, a semiconductor device using a nitride semiconductor.
In recent years, attention has been paid to semiconductor devices each using a III-V group compound having a larger bandgap than that of silicon (Si). Among them, a MISFET using gallium nitride (GaN) has advantages such as 1) large breakdown electric field, 2) large saturated electron velocity, 3) large thermal conductivity, 4) being able to form a favorable hetero junction between AlGaN and GaN, and 5) being a nontoxic and high-safety material.
For example, in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2010-109086), there is disclosed a nitride semiconductor device in which a p-GaN layer is arranged under a channel layer formed of an undoped GaN layer. Then, the p-GaN layer is electrically coupled with a source electrode, thereby to achieve a high avalanche resistance and high reliability.